Various manual and powered tools for installing and removing tires from wheel rims are known. In a manual version such tools generally comprise an elongated pry bar handle, which is gripped by a user, and a flattened tool end for insertion between the tire bead and the wheel rim. The bead of a tire is generally wire reinforced and resists deformation. The bead is usually intended to seal a mounted tire to the wheel rim. For this purpose the bead has a diameter that is somewhat less than the diameter of the wheel rim flange and resides between the spaced flanges of the wheel rim. The bead resists stretching and is urged axially against the rim and sealed to the rim, inter alia, by pneumatic pressure in the tire or in an inner tube in the tire.
To remove a tire from a rim, the beads are unsealed or “broken” by moving them axially inwardly to disengage from sealing engagement with the rim. Then the two beads and sidewalls of the tire are passed axially over one of the rim flanges to remove the tire from the rim. Inasmuch as the diameter of the bead is less than that of the rim, this involves forcing the bead over the rim, by stretching the bead and/or deforming the bead into an oval and moving the longer dimension of the oval around the rim.
A working end of a tool is typically inserted between the tire bead and the rim flange. The user then applies pressure to the opposite handle end, using the tool as a lever and the wheel rim as a fulcrum. A short length of the tire bead is thereby lifted axially over the rim flange. This process is repeated in successive stages to increase the length of the bead on the axial outside of the rim flange, often using two or three pry tools around the periphery of the wheel rim to hold a portion of the bead against popping back over the rim flange while more of the bead is pried over the rim flange. After a certain angular span of the bead has been passed over the rim flange, prying at a distance from that span (e.g., at a diametrically opposite position) pulls the bead portion that is already outside the rim radially inwardly on the outside, rather than tending to pull that portion back between the rim flanges. It thus becomes easier to pass the remainder of the bead axially over the rim until the entire tire bead resides outside the rim.
Powered machines are available to serve the same function. Using such devices, the wheel is typically mounted on a spindle and the bead is broken. A short length of the tire bead is then pried over the rim flange, and a tool is placed under the lifted bead and engaged with a driving shaft on the spindle. An end of the tool is then passed circumferentially around the periphery of the wheel rim flange, pulling the entire bead over the rim flange.
With each of the above techniques, in order to fully remove the tire from the rim, the opposite side bead must be passed over the same rim flange as the first bead, in a similar manner. For installing a tire on a wheel rim, the foregoing process is carried out in reverse order, manually or using powered means.
Recently, truck tire manufacturers have introduced tires that are sized to take the place the traditional “dual tire” pairs used for trailer applications. These new tires are significantly wider than either of the single width tires they replace. As such, they can also have significantly deeper wheel rims, which can complicate the removal process when using current tools as described above.
Often, truck tires must be replaced on the roadside, such as when a truck driver experiences a flat on the highway. In such cases, the driver usually calls ahead for roadside assistance, rather than attempt to change the tire himself. Thus, a desirable tool for performing the above functions should be compact for easy storage and transportation. Additionally, since it can be expected that flats will occur in the winter, the tool should reduce or eliminate the need for the user to stand on the tire or wheel rim to remove and install a tire on a rim. This would reduce the chance that the user could slip and injure himself when applying the forces to the handle necessary to operate the tool.
Furthermore, it may be an advantage to allow a damaged tire to be removed and a new tire installed on a wheel rim without removing the wheel rim from the vehicle. This can be of particular advantage for utility vehicles, such as backhoes, etc, where the wheels are particularly large and may be difficult to remove from the associated vehicle axle. It is also advantageous because it can speed the overall tire replacement process.
Thus, there is a need for an easy to use tool that is effective for installing and removing any of a wide variety of sizes of tires from their associated wheel rims, including newer truck tires having significantly wider wheel rims, and which can be used by the operator in a safe manner, even in inclement weather.